NYC - my tenant hasn’t paid rent in 7 months

My tenant stopped paying rent 7 months ago. I am small landlord, owning 1 single family house which I trusted these tenants with. I renovated and made a beautiful home for my family to live there but then I found out about my third pregnancy. Made a big (and stupid) decision to not move in to my new house and stayed at my old place (as tenants) to stay close to my parents for childcare support (I have 3 small children). how could they screw me over like this? This lady has a small kid. How could she not understand? She started a business for eyebrows, eyelash, facials, created her own cosmetics line while withholding rent from me. Her husband works too.They don't pick up our calls. How does it work like that? Can anyone give me any advice? We went to a lawyer and initiated a 90 day notice to the tenants which is supposed to end Dec 31st. We are paying rent where we stay also paying mortgage out of our pocket for the delinquency on their part. We are not going to sustain like this. It's so difficult. What do I do?